import test from 'node:test';
import assert from 'node:assert/strict';
import { spawn } from 'node:child_process';
import { fileURLToPath } from 'node:url';

import { createServer } from '../server.js';

const REPO_ROOT = fileURLToPath(new URL('..', import.meta.url));

async function withServer(fn) {
  const server = createServer();
  await new Promise((resolve) => server.listen(0, '127.0.0.1', resolve));
  const { port } = server.address();
  const base = `http://127.0.0.1:${port}`;
  try {
    await fn(base);
  } finally {
    await new Promise((resolve) => server.close(resolve));
  }
}

function post(base, body) {
  return fetch(`${base}/api/generate`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(body),
  });
}

test('the API rejects unparseable booleans with a 400 naming the option', async () => {
  await withServer(async (base) => {
    const response = await post(base, {
      mode: 'random',
      length: 16,
      useLower: 'maybe',
      useUpper: false,
      useDigits: false,
      useSymbols: false,
    });

    assert.equal(response.status, 400);
    const payload = await response.json();
    assert.match(payload.error, /useLower/);
  });
});

test('the API accepts "no" as false', async () => {
  await withServer(async (base) => {
    const response = await post(base, {
      mode: 'random',
      length: 16,
      useLower: 'no',
      useUpper: false,
      useDigits: true,
      useSymbols: false,
    });

    assert.equal(response.status, 200);
    const payload = await response.json();
    assert.equal(payload.passwords.length, 1);
    assert.ok(!/[a-z]/.test(payload.passwords[0].value), 'expected no lowercase characters');
  });
});

test('the API rejects invalid custom symbol sets with a 400', async () => {
  await withServer(async (base) => {
    const cases = [
      ['a b', /whitespace/],
      ['a\tb', /control characters or whitespace/],
      ['x'.repeat(65), /at most 64/],
    ];

    for (const [customSymbols, pattern] of cases) {
      const response = await post(base, {
        mode: 'random',
        length: 16,
        useLower: false,
        useUpper: false,
        useDigits: false,
        useSymbols: true,
        customSymbols,
      });

      assert.equal(response.status, 400, `expected 400 for ${JSON.stringify(customSymbols)}`);
      const payload = await response.json();
      assert.match(payload.error, pattern);
    }
  });
});

test('the API never splits astral characters', async () => {
  await withServer(async (base) => {
    const response = await post(base, {
      mode: 'random',
      length: 12,
      useLower: false,
      useUpper: false,
      useDigits: false,
      useSymbols: true,
      customSymbols: '😀',
      requireEach: true,
    });

    assert.equal(response.status, 200);
    const payload = await response.json();
    const value = payload.passwords[0].value;
    assert.ok(!/[\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?<![\uD800-\uDBFF])[\uDC00-\uDFFF]/.test(value));
    assert.equal(Array.from(value).length, 12);
    for (const codePoint of Array.from(value)) {
      assert.equal(codePoint, '😀');
    }
  });
});

test('the API labels an upper bound entropy as approximate', async () => {
  await withServer(async (base) => {
    const constrained = await post(base, {
      mode: 'random',
      length: 16,
      useLower: true,
      useUpper: true,
      useDigits: true,
      useSymbols: true,
      requireEach: true,
    });
    const constrainedPayload = await constrained.json();
    assert.equal(constrainedPayload.entropyApproximate, true);
    assert.equal(constrainedPayload.passwords[0].entropyApproximate, true);
    assert.match(constrainedPayload.entropyNote, /upper bound/);

    const plain = await post(base, {
      mode: 'random',
      length: 16,
      useLower: true,
      useUpper: true,
      useDigits: true,
      useSymbols: true,
      requireEach: false,
    });
    const plainPayload = await plain.json();
    assert.equal(plainPayload.entropyApproximate, false);
    assert.match(plainPayload.entropyNote, /exact/);

    const memorable = await post(base, { mode: 'memorable', words: 4, digits: 2 });
    const memorablePayload = await memorable.json();
    assert.equal(memorablePayload.entropyApproximate, false);
  });
});

test('SIGTERM stops the server quickly', async () => {
  const port = 34567;
  const child = spawn(process.execPath, ['server.js'], {
    cwd: REPO_ROOT,
    env: { ...process.env, PORT: String(port) },
    stdio: ['ignore', 'pipe', 'pipe'],
  });

  try {
    const base = `http://127.0.0.1:${port}`;
    const deadline = Date.now() + 10000;
    for (;;) {
      try {
        const response = await fetch(`${base}/healthz`);
        if (response.ok) break;
      } catch {
        // not up yet
      }
      if (Date.now() > deadline) throw new Error('server did not start in time');
      await new Promise((resolve) => setTimeout(resolve, 50));
    }

    const started = Date.now();
    const exit = await new Promise((resolve) => {
      child.once('exit', (code, signal) => resolve({ code, signal }));
      child.kill('SIGTERM');
    });
    const elapsed = Date.now() - started;

    assert.equal(exit.code, 0, `expected a clean exit, got code ${exit.code} signal ${exit.signal}`);
    assert.ok(elapsed < 4000, `expected the shutdown to be quick, took ${elapsed}ms`);
  } finally {
    if (child.exitCode === null && child.signalCode === null) {
      child.kill('SIGKILL');
    }
  }
});

test('SIGINT stops the server quickly', async () => {
  const port = 34568;
  const child = spawn(process.execPath, ['server.js'], {
    cwd: REPO_ROOT,
    env: { ...process.env, PORT: String(port) },
    stdio: ['ignore', 'pipe', 'pipe'],
  });

  try {
    const base = `http://127.0.0.1:${port}`;
    const deadline = Date.now() + 10000;
    for (;;) {
      try {
        const response = await fetch(`${base}/healthz`);
        if (response.ok) break;
      } catch {
        // not up yet
      }
      if (Date.now() > deadline) throw new Error('server did not start in time');
      await new Promise((resolve) => setTimeout(resolve, 50));
    }

    const started = Date.now();
    const exit = await new Promise((resolve) => {
      child.once('exit', (code, signal) => resolve({ code, signal }));
      child.kill('SIGINT');
    });
    const elapsed = Date.now() - started;

    assert.equal(exit.code, 0, `expected a clean exit, got code ${exit.code} signal ${exit.signal}`);
    assert.ok(elapsed < 4000, `expected the shutdown to be quick, took ${elapsed}ms`);
  } finally {
    if (child.exitCode === null && child.signalCode === null) {
      child.kill('SIGKILL');
    }
  }
});